Operating Controls - Henry Radio 3K -Classic Operating And Maintenance Manual

SECTION 3 OPERATING CONTROLS
SECTION 3 .1 FRONT PANEL CONTROLS
OFF/ON POWER SWITCH - This switch is used for turn-
ing the amplifier on and off. It is also a circuit breaker
for overload protection on the AC lines. When the
3K-Classic is turned off or the amplifier is in standby,
the output of the exciter passes through the amplifier
directly to the antenna.
MULTIMETER AND RELAY CONTROL SWITCHES -
These push switches are located below the multimeter.
There are two interlocked pairs. The two on the left
allow the operator to use either the 10,000 volt scale
or the 100 ma scale for grid current on the multimeter.
The right pair enables or disables the control circuitry of
the amplifier. This makes it possible fo r the operator to
use the exciter alone without turning off the power
switch of the amplifier.
CW/SSB SWITCH - this 2-position rotary switch selects
between two plate voltages to assure correct loading and
output for each type of emission.
PLATE CURRENT METER - This meter monitors the
plate current of the 8877 tube. Nominal plate current
is between 800 and 900 ma for full output.
PILOT LIGHTS - When the amplifier is turned on, the
dial lights wi" come on indicating that the POWER
switch is on.
FUSES - There are (2) 3AG 11/2 amp fuses. One is for the
meter circuit. The other is for the blower and low volt-
age control circuit.
LOAD CONTROL - This control matches the amplifier's
output network to the load. Refer to the calibration
table for appropriate initial settings for the frequency
range desired. A LOAD setting of 0 (zero) corresponds
to minimum loading and a LOAD setting of 100 corres-
ponds to maximum load capacitor mesh.
TUNE CONTROL - The TUNE control is a 20-turn
vernier dial connected to the variable inductance tank
coil. The TUNE control reading can be used in con-
junction with the setting given in the calibration table to
adjust the tank coil for the approximate tuning range to
be used.
BAND SWITCH - The BAND switch selects the necessary
input and output circuits for the amplifier to operate in
anyone of the following frequency ranges:
80 3.500 to 4.000 MHz
40 7.000 to 7.500 MHz
20 14.000 to 14.500 MHz
15 21.000 to 21.500 MHz
10 28.000 to 30.000 MHz (Ex-
port and military sales only)
The amplifier can be operated on many frequencies
outside these bands by switching the amplifier to the
band closest in frequency to the desired operating
frequency. Never move the BAND switch when the
amplifier is keyed.
SECTION 3.2 REAR PANEL CONTROLS
ALC JACK - This socket accepts an RCA phono plug (an
ALC cable is provided in the accessory packet of the
amplifier). The ALC feedback to the exciter is available
at this socket.
ALC ADJUSTMENT POTENTIOMETER - This po-
tentiometer controls the sensitivity of the 3K-Classic
circuit. Refer to the operating instructions for the
adjustment procedure.
RELAY CONTROL JACK - The RELAY CONTROL
jack accepts an RCA phono plug (a relay cable is pro-
vided in the accessory packet of the amplifier). When the
socket is shorted to ground, the amplifier's antenna
relay closes. If the amplifier is turned off the relay wi"
not key. Never apply any voltage to this socket.
RF INPUT CONNECTOR - This BNC coax connector
accepts the drive line from the exciter. The input im-
pedance of the amplifier is 50 ohms.
RF OUTPUT CONNECTOR - The nominal output
impedance of the amplifier is 50 ohms. Do not operate
the equipment without a load, or into a load with an
SWR of more than 2:1. Use only RG-8/U coax (or its
equivalent) to connect this 50-239 connector to ap-
propriate antenna or dummy load.
GROUND LUG - This lug is provided to ground the
amplifier. Connecting the amplifier to a standard 3 pin
electrical system is usually adaquate grounding. If such a
system is not used, it is wise to ground the unit using the
ground lug and connecting it to a good earth ground to
prevent radiated interference or the danger of electrical
shocks.
CATHODE FUSE - This 8 AG, 1.5 amp fuse protects the
cathode circuit from shorts. Never exceed the recom-
mended current rating when replacing the fuse.
POWER CORD - The power cord must be connected to
an appropriate power source. No power plug is provided.
Be certain that the power transformer is jumpered
correctly for the appropriate line voltage. See Figure 1.